You need to read you some brewing history......
Besides the afore mentioned Kvass, bigwhitt might be referring to the ancient Mesopotamian/sumerian brewing techniques of using a bread baked specifically for making BEER. The bread was called Bappir.
The Beer was chronicled in the Story of Gilgamesh and the
Hymn to Ninkasi who is is the ancient Sumerian matron goddess of BEER.
Anchor brewing a looooong time ago brewed a version of this beer. And the Maltose Falcon's Homebrew club posted their adventured with brewing a bappir based beer here. (With the recipe. Sadly the photo essay link that shows what Bappir looks like and the brew session is broken.)
http://archive.maltosefalcons.com/recipes/20051002.php
Here is a downloadable MS Word article and recipe for another version of it
http://www.google.com/url?sa=t&sour...sg=AFQjCNGHRX-RzNMG7wHQCMH1hbf16sm8PQ&cad=rja
Theres also the Beer from King Mida's Tomb, that Dogfish Head Replicated, "Mida's Touch" you're interested in the history, here's some articles on the original discovery and the deconstructing of the ingredients and reproducing the funeral feast.
http://www.penn.museum/sites/Midas/intro.shtml
http://findarticles.com/p/articles/mi_m3469/is_45_53/ai_94673455
A couple years back I cooked all the dishes in the original last meal and served Midas Touch, it was pretty interesting.
Hope this helps!!!